Decades ago, the rise in demand for telephony services spurred on the deployment of high capacity optical fiber networks. The subsequent rise in demand for Internet services resulted in leveraging of such optical networks for transmission of IP packets in an IP-over-Optical communication scheme. Such a multi-layer configuration utilizes the IP routers for controlling networking functions and the optical network for providing high throughput communication paths between the IP routers.
The communication path disruption can result from scheduled or unscheduled maintenance activities or from fiber failures, e.g. physical failure due to fiber severing or equipment failures, and can result in a communication traffic slowdown or a partial e.g. time limited, or complete interruption of communication traffic through a portion of the network.